What DeepSeek Is (and Isn't)

DeepSeek is worth knowing about for a genuine technical reason — and worth using carefully for an equally genuine security reason. This course covers both honestly, because that's the only responsible way to teach it.

DeepSeek is a Chinese AI lab whose models (R1, V4, and others) became notable for offering frontier-level reasoning capability at a small fraction of the cost of comparable Western models. Its API pricing runs at a fraction of a cent per million tokens on its lighter models, and its reasoning model has been benchmarked as competitive with OpenAI's o1-class reasoning models at a dramatically lower price. That cost story is the entire reason DeepSeek became a major talking point in the AI industry.

It's also open-weight, meaning DeepSeek publishes its model weights publicly — a meaningfully different approach from the closed models behind ChatGPT, Gemini, Claude, and Copilot. Researchers and developers can run DeepSeek's models on their own infrastructure rather than only through DeepSeek's own app or API.

Access — genuinely free, genuinely cheap

• Web and mobile chat app (chat.deepseek.com and official apps) — free, no subscription, no paywall.
• API — priced per token, with new accounts receiving several million free tokens to start, no credit card required.

What DeepSeek is not — and this is the point of this course

• It's not a tool to treat the same as this library's other assistants without reading the next two lessons. The concerns here are more serious and more directly documented than for any other tool in this library — not a vague trust concern, but specific, independently verified findings and formal government bans.
• It's not something this course is telling you never to use. It's genuinely capable and genuinely cheap, and that's real. The goal here is informed use, not a blanket verdict — you decide what that means for you, with the actual facts.
• It's not appropriate for any organization already under specific data-residency, government-contract, or regulatory-compliance obligations to use without first clearing it through whoever handles compliance at that organization — covered fully in Lesson 4.

▶️ Before the next lesson

Before trying DeepSeek on anything, read Lesson 4 of this course first — this is the one course in this library where the order matters.